Vibrational Raman scattering from high T sub c single crystals.

Polarized Raman spectra have been measured on single crystals of the high T sub c materials A sub 2 BCu sub 3 0 sub x with A=Ba and Sr, B=Y and La and 67. The dependence of the 500 cm sup (-1) peak position (Alpha sub (zz)) on chemical composition is in agreement with its assignment to the 0(1) axial stretching vibration. The intensity of the 600 cm sup (-1) band, which has been ascribed to a defect induced Cu-0 mode, strongly depends on the crystal preparation and resulting purity.